The purpose of this research is to determine whether L-phenylalanine mustard (alkeran, myleran, sarcolysin, L-PAM) is in any way unique in its mechanism of cytotoxic action on cancer cells. Its uptake, distribution, alkylation and repair patterns in mouse myeloma cells will be determined and compared to that of related compounds. Localization in nucleic acid will be studied as to type of chemical adduct and the kind of polynucleotide affected. The effects on RNA transcription, DNA biosynthesis and repair will be evaluated. These parameters will be compared using L-PAM resistant tumors or tissue culture preparation.